Spinning punch



April 25, 1961 I y #0 l i l l3 /4 l Y 1 I i ''1 ii if I INVENTOR.fi/CHARD A. AHA/N amt-5m- ATTORNEYS United tc atent 2,981,137 C16 IPatented r. as, 1961 SPINNING PUNCH Richard -A. Sahlin, Fairfield,Conn., assignor to Remington Arms Company, Inc.,-Bridgeport, Conn., acorporation of Delaware Filed Mar. 13, 1958, Ser. No. 721,267

7 9 Claims. (Cl. 86-32) As more fully described in the patent toReynolds,

No. 2,313,265, the priming material is a pulverulent admixture of properingredients, and a measured charge thereof containing just enoughmoisture to form a coherent pellet is placed loose in the shell andthereafter distributed into the rim by an appropriately shaped spinningpunch. It is desirable that insofar as practicable all of the mixture beplaced within the hollow rim, instead of being spread over themid-portion of the shell head or smeared on the cylindrical wall of theshell. The presence of a layer of mixture on the midportion of the flathead is harmless but useless since the firing pin of the gun impacts therim. A smear of the mixture on the interior cylindrical wall of theshell is definitely unwanted. It is further desirable that the mixturebe tightly compacted in the rim, to avoid dislodgment in the handling ofthe shells incident to the loading of completed cartridges or underimpact of the firing pm.

The present invention contemplates a spinning punch or centrifugaldispensing impeller tool which is substantially more eiiective in theaccomplishment of these objectives than punches hitherto used.

In the drawings:

Fig. 1 is an end view of a spinning punch embodying the presentinvention.

Fig. 2 is a fragmentary side elevation of the punch, partly within ashell having a pellet of priming mixture therein. The elevation is inthe direction indicated by line 2-2 of Fig. 1.

Fig. 3 is a side elevation of the punch in the direction indicated by 3-3 of Fig. l, the punch being in working position within the shell andhaving completed the distribution of the priming mixture into the shellrim.

The head portion of the shell S comprises a hollow rim or peripheralcavity C adapted to receive the priming composition which is introducedinto the shell in the form of a pellet P.

"The spinning punch comprises a cylindrical shank of such diameter as tobe received within the shell with cut-outs have been illustrated, eachhas a maximumdepth adjacent the end wall 12 and diminishes both in depthlengthwise of the punch and in width radially of the punch as it recedesfrom said end wall. The narrow end of each floor 13 intersects the wall12 of the adjacent a cut-out in a terminal line identified by numeral14.

Each floor 13 is inclined to the end face 11 at a predetermined anglewhich preferably increases from the deep end to the shallow end of thecut-out. The inclination of the floor is critical, and the dimensions ofthe slot or notch formed by the intersection 14 of each cut-out withtheadjacent cut-out are critical.

Referring particularly to Fig. 3, it will be noted that margin 14together with the bounding walls, of the cavity C determine thecross-sectional area and hence the volume of the annular space whichreceives .the priming mixture. It is important that the volume thusdetermined be equal to but not materially exceed the ,volume of thepellet P. If the mixture-receiving space is greaterthan the volume ofpellet P the mixture is only loosely dis-- tributed into the receivingspace, instead of being coma minimum of clearance between thecylindrical parts pacted therein in the manner necessary to insure thatit will remain in place in subsequent handling of the shell. On theother hand, if the receiving space is materially less than the volume ofpellet P, the mixture tends to be extruded into the gap between theshank of the punch and the periphery of the shell, leaving anundesirable smear on the shell interior. It is also important that thejunction of the margin 14 with the periphery of the shank besubstantially opposite the end of-the cylindrical portion of the shell;or, in other words, that the height H of the slot defined by the margin14 be substantially equal to the maximum height of the cavity C. In use,the punch rotates in the direction indicated by the arrow in Fig. 3. Asthe punch approaches the shell head the material of pellet P isdisplaced into the cut-outs and is centrifugally moved toward the smallends of the cut-outs, through cut-out terminal slots defined by margin14, and into the cavity .C. The angle of inclination of the cut-outfloors 13 should be such as to facilitate the outward or radial movementof the mixture, rather than merely confining it between the punch. andthe interior of the shell head; since, as above stated, any primingcomposition remaining on the mid-portion of the shell head is wasted. Ithas been found that the minimum angle of inclination of the floors 13necessary to leave a substantially clean shell head is about 20. At aminimum angle of 15 the cavity C can be properly filled, a layer ofmixture of tolerable thickness remaining on the mid-portion of the shellhead. This is the inclination of each floor 13 adjacent the end wall 12.Preferably, the inclination progressively increases toward theexit'margin 14, the total increase being from about 4 to about 10. Theinclination of floor 13 adjacent the end wall 12 may vary from 15 toabout 40, and its inclination adjacent the margin 14 may vary from 20 toabout 45. Optimum results have been secured with a minimum floorinclination of 36 and a maximum of 40; it being remembered, as abovestated, that the height of the gap defined by margin 14 should notdiffer substantially from the maximum height of the shell rim cavity,and that the volume defined by margin 14 and the wall of cavity C shouldnot differ materially from the volume of the charge to be placed in thecavity C.

Punches made in accordance with the present invention have been foundespecially useful in the distribution of priming compositions which arecharacterized by the absence of an abrasive of the type of ground glass,these mixtures not being amenable to distribution by the kind of puncheshitherto used.

What is claimed is:

1. A spinning centrifugal dispensing impeller tool for distributing ameasured charge of a moist and pulverulent initiating explosivecomposition into an annular cavity of a cartridge case having acontinuous open mouth of predetermined width facing said tool; said toolcomprising a cylindrical shank and a tip comprising an end face in aplane substantially perpendicular to the axis of said shank and aplurality of cut-outs intersecting said end face and the periphery ofsaid shank, each cut-out comprising an end wall in' a planesubstantially parallel to said axis, and a spiral floor disposed at anangle of not less than 15 to said end face, the said tool adapted torotate in use in a direction such that the end wall is the leadingportion of the turning cut-out and the spiral floor is the trailingportion of the turning cut-out.

2. A tool according to claim 1, in which the spiral floor of eachcut-out intersects the end wall of an adjacent cut-out in a linedisposed at an angle not less than 20 to the plane of said end face.

3. A tool according to claim 2, in which said line intersects theperiphery of said shank at a distance from said end face which issubstantially equal to the height of a cavity in which the compositionis being distributed.

4. A tool according to claim 2, in which the angle of said spiral floorto the plane of said end face varies uniformly from end to end of saidfloor.

5. A tool according to claim 4, in which the angle of the spiral floorof each cut-out to the end face of the 7 tool is a at the end wall ofsuch cut-out and a maximum at the intersection of said floor with theend wall of the adjoining cut-out.

6. A tool according to claim 5, in which the crosssectional area of eachcut-out diminishes from a maximum at the end wall of said cut-out to aminimum at the intersection of said floor with the end wall of theadjacent cut-out.

7. A tool according to claim 6, in whichythe minimum angle of said floorto the plane of the end face of said tool is between 15 and and themaximum angle of said floor to the plane of the end face of said tool isbetween 20 and 8. A tool according to claim 7, in which the volumedefined by the wall of an annular cavity to be filled by said tool andthe path of movement of the small end of said cut-outs is substantiallyequal to the volume of said measured charge. y

9 A tool according to claim 8, in which the maximum dimension of thesmall end of each cut-out parallel to the axis of the tool doesynotdiffer materially from the width of the mouth of an annular cavity to befilled by said tool.

Powers Apr. .24, 1866 Marini Apr. 24, 1945

